/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xml.utils;

/**
 * A very simple table that stores a list of strings, optimized
 * for small lists.
 *
 * @xsl.usage internal
 */
public class StringVector implements java.io.Serializable {
    static final long serialVersionUID = 4995234972032919748L;

    /**
     * @serial Size of blocks to allocate
     */
    protected int m_blocksize;

    /**
     * @serial Array of strings this contains
     */
    protected String m_map[];

    /**
     * @serial Number of strings this contains
     */
    protected int m_firstFree = 0;

    /**
     * @serial Size of the array
     */
    protected int m_mapSize;

    /**
     * Default constructor.  Note that the default
     * block size is very small, for small lists.
     */
    public StringVector() {

        m_blocksize = 8;
        m_mapSize = m_blocksize;
        m_map = new String[m_blocksize];
    }

    /**
     * Construct a StringVector, using the given block size.
     *
     * @param blocksize Size of the blocks to allocate
     */
    public StringVector(int blocksize) {

        m_blocksize = blocksize;
        m_mapSize = blocksize;
        m_map = new String[blocksize];
    }

    /**
     * Get the length of the list.
     *
     * @return Number of strings in the list
     */
    public int getLength() {
        return m_firstFree;
    }

    /**
     * Get the length of the list.
     *
     * @return Number of strings in the list
     */
    public final int size() {
        return m_firstFree;
    }

    /**
     * Append a string onto the vector.
     *
     * @param value Sting to add to the vector
     */
    public final void addElement(String value) {

        if ((m_firstFree + 1) >= m_mapSize) {
            m_mapSize += m_blocksize;

            String newMap[] = new String[m_mapSize];

            System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);

            m_map = newMap;
        }

        m_map[m_firstFree] = value;

        m_firstFree++;
    }

    /**
     * Get the nth element.
     *
     * @param i Index of string to find
     * @return String at given index
     */
    public final String elementAt(int i) {
        return m_map[i];
    }

    /**
     * Tell if the table contains the given string.
     *
     * @param s String to look for
     * @return True if the string is in this table
     */
    public final boolean contains(String s) {

        if (null == s)
            return false;

        for (int i = 0; i < m_firstFree; i++) {
            if (m_map[i].equals(s))
                return true;
        }

        return false;
    }

    /**
     * Tell if the table contains the given string. Ignore case.
     *
     * @param s String to find
     * @return True if the String is in this vector
     */
    public final boolean containsIgnoreCase(String s) {

        if (null == s)
            return false;

        for (int i = 0; i < m_firstFree; i++) {
            if (m_map[i].equalsIgnoreCase(s))
                return true;
        }

        return false;
    }

    /**
     * Tell if the table contains the given string.
     *
     * @param s String to push into the vector
     */
    public final void push(String s) {

        if ((m_firstFree + 1) >= m_mapSize) {
            m_mapSize += m_blocksize;

            String newMap[] = new String[m_mapSize];

            System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);

            m_map = newMap;
        }

        m_map[m_firstFree] = s;

        m_firstFree++;
    }

    /**
     * Pop the tail of this vector.
     *
     * @return The String last added to this vector or null not found.
     * The string is removed from the vector.
     */
    public final String pop() {

        if (m_firstFree <= 0)
            return null;

        m_firstFree--;

        String s = m_map[m_firstFree];

        m_map[m_firstFree] = null;

        return s;
    }

    /**
     * Get the string at the tail of this vector without popping.
     *
     * @return The string at the tail of this vector.
     */
    public final String peek() {
        return (m_firstFree <= 0) ? null : m_map[m_firstFree - 1];
    }
}
